1. Field of the Invention
The present invention relates to an electromagnetic wave analyzing apparatus for analyzing the electromagnetic field intensity, etc. of an electromagnetic wave radiated from an electronic apparatus or the like, based on net pattern information concerning a net pattern obtained by modeling the electronic apparatus or the like under analysis (electromagnetic waves existing within a specific frequency range are called xe2x80x9cradio wavesxe2x80x9d). The invention also relates to a computer readable storage medium for the same.
EMC (electromagnetic compatibility) rules tend to become more stringent year by year, imposing severer restrictions on the electromagnetic field intensity of electromagnetic waves that various appliances such as electronic apparatuses are allowed to radiate when put in operation as products. It is therefore a pressing issue to take measures to cope with the electromagnetic waves that such electronic apparatuses radiate. As one of the measures to cope with this issue, it is becoming important to form a plurality of net patterns by modeling an appliance such as an electronic apparatus by means of a simulation technique, and to calculate rapidly and accurately the electromagnetic field intensity, etc. of electromagnetic waves generated within each of these net patterns, by using electromagnetic wave analyzing software as a tool.
2. Description of the Related Art
When analyzing an electromagnetic wave radiated from an appliance such as an electronic apparatus, if information about the arrangement of net patterns is acquired as net pattern information from a CAD (computer aided design) system, a model for electromagnetic wave analysis can easily be constructed by modeling the above appliance. The information about the arrangement of net patterns referred to here represents information showing positions in which electronic components within the electronic apparatus are mounted.
To facilitate understanding of a problem associated with a prior art electromagnetic wave analyzing method, one example of the prior art electromagnetic wave analyzing method will be described below, with reference to FIG. 1 that will be described later in xe2x80x9cBRIEF DESCRIPTION OF THE DRAWINGSxe2x80x9d.
A schematic diagram showing one example of a prior art net pattern used for electromagnetic wave analysis, is illustrated in FIG. 1.
Generally, by modeling an electronic apparatus for electromagnetic wave analysis, a net pattern N, as shown in FIG. 1, is obtained. It should be noted that one of a plurality of net patterns is typically shown as the net pattern N in FIG. 1. In an actual electronic apparatus, since various electronic components are mounted at high density on a printed circuit board, the space for a wiring of the components tends to be reduced, and the net pattern has to be bent at small pitches or small distances. As a result, the net pattern N is usually made up of many segments (also called line segments) S and terminal points P connecting adjacent segments with each other. Some of these terminal points P may also includes branching points each for branching one segment into two or more segments. When analyzing the electromagnetic field intensity, etc. of electromagnetic waves in such a net pattern, since each of these segments is calculated as one element which generates a radiation of the electromagnetic waves, the time required to analyze the electromagnetic waves tends to increase as the number of segments increases.
As described above, according to the prior art, when analyzing electromagnetic waves in a plurality of net patterns established for an electronic apparatus or the like, it has been necessary to calculate the electromagnetic field intensity, etc. of the electromagnetic waves radiated from each of the segments in the net patterns.
Since there are usually approximately 100 to 200 kinds of net patterns on each of the printed circuit boards mounted in an electronic apparatus, the time required for such an analysis becomes correspondingly longer.
Besides, there are cases in which data of six kinds of net patterns involve approximately 1500 segments, as reported in one example; in such cases, it takes as many as 40 hours to complete the calculation for such net pattern data.
In other words, if information about the arrangement of net patterns established based on the mounting positions of various electronic components on a printed circuit board is directly used as net pattern information from a CAD system, the total number of segments will become very large and an enormous amount of time will be required for the analysis of electromagnetic waves radiated from an electronic apparatus or the like.
The present invention has been devised in view of the above problem, and it is an object of the present invention to provide an electromagnetic wave analyzing apparatus that can reduce the time required for electromagnetic wave analysis as much as possible without affecting the accuracy of the electromagnetic wave analysis, and also to provide a computer readable storage medium for use in the electromagnetic wave analyzing apparatus. The term xe2x80x9ccomputer readable storage mediumxe2x80x9d used herein means a storage medium from which data can be read out by using a computer.
To achieve the above object, the electromagnetic wave analyzing apparatus of the present invention includes an electromagnetic wave analyzing unit for analyzing electromagnetic waves radiated from an appliance, on the basis of net pattern information concerning a net pattern obtained by modeling the appliance under analysis, and comprises a coordinates data extracting unit for extracting, from the net pattern information, coordinates data defining the coordinates of each of terminal points of a plurality of segments constituting the net pattern; and a net pattern smoothing unit for dividing the net patterns, based on the coordinates data extracted by the coordinates data extracting unit, into object sections each containing a prescribed number of segments so that the length of each of the object sections is not greater than a predetermined maximum length, and for carrying out smoothing of the net pattern for each object section, by replacing the prescribed number of segments contained in the object section with a single straight line or a plurality of straight lines smaller in number than the number of the segments.
The electromagnetic wave analyzing apparatus of the above configuration is constructed so that the coordinates data for which the smoothing has been completed is input to the electromagnetic wave analyzing unit for calculation of the electromagnetic field intensity of the electromagnetic waves.
Preferably, in the electromagnetic wave analyzing apparatus of the present invention, the net pattern smoothing unit carries out the smoothing for the each object section by selecting an arbitrary intermediate point located between coordinates defining a start point of the object section and coordinates defining an end point thereof, and by setting the coordinates of the intermediate point so that the sum of the distance between the start point and the intermediate point and the distance between the intermediate point and the end point is equal to the combined length of the prescribed number of segments contained in the object section, and the coordinates data containing the coordinates of the start point, intermediate point, and end point of the object section, for which the smoothing has been completed, is input to the electromagnetic wave analyzing unit.
Further, preferably, in the electromagnetic wave analyzing apparatus of the present invention, the net pattern smoothing unit carries out the smoothing for each object section, by replacing the prescribed number of segments contained in the object section with a straight line joining the start point and end point of the object section, and the coordinates data containing the coordinates of the start point and end point of the object section, for which the smoothing has been completed, is input to the electromagnetic wave analyzing unit.
Further, preferably, in the electromagnetic wave analyzing apparatus of the present invention, the net pattern smoothing unit carries out the smoothing for each object section, by replacing the prescribed number of segments contained in the object section with two straight lines consisting of a first directional component and a second directional component joining the start point and end point of the object section, and the coordinates data containing the coordinates of the start point and end point of the object section, for which the smoothing has been completed, is input to the electromagnetic wave analyzing unit.
The present invention also provides a computer readable storage medium used for analyzing electromagnetic waves radiated from an appliance, on the basis of net pattern information concerning a net pattern obtained by modeling the appliance under analysis, the storage medium having stored therein means for extracting, from the net pattern information, coordinates data defining the coordinates of each of terminal points of a plurality of segments constituting the net pattern; means for dividing the net pattern, based on the extracted coordinates data, into object sections each containing a prescribed number of segments so that the length of each of the object sections is not greater than a predetermined maximum length, and for carrying out smoothing of the net pattern for each object section, by replacing the prescribed number of segments contained in the object section with a single straight line or a plurality of straight lines smaller in number than the number of the segments; and means for calculating the electromagnetic field intensity of the electromagnetic waves, on the basis of the coordinates data for which the smoothing has been completed.
In summary, in the present invention, since the number of segments can be reduced by carrying out the smoothing of the net pattern without substantially affecting the accuracy of electromagnetic wave analysis, the time required for the analysis of electromagnetic waves can be drastically reduced without degrading the accuracy of the electromagnetic wave analysis.